Which organ is part of two different systems?

There are quite a few of them: here are some

1) Thymus: endocrine and lymphatic systems

2) Pharynx: respiratory and digestive system

3) Pancreas: digestive and endocrine system

4) Mammary glands: integumentary and reproductive systems

For example, the human digestive system is an organ system in which the mouth and esophagus ingest food, the stomach crushes and liquefies it, the pancreas and gall bladder make and release digestive enzymes, and the intestines absorb nutrients into the blood. An organ can be part of more than one organ system.